If you've ever downed a whole bag of Chex Mix then flipped over the bag and found that's about eight servings, you probably know serving sizes bear little relation to what people are actually eating. For years, consumer advocacy groups have been pushing the F.D.A. to change portion sizes, and now in an effort to light a fire under the agency, the Center for Science in the Public Interest has singled out some of the most ridiculous serving suggestions.

The New York Timesreports that the F.D.A. regulates what serving sizes food manufacturers can list on packages based on what a person would "customarily consume." The problem is this research was carried out in the 1970s, and back then the average American wasn't eating dinners that could feed a family of three.

The Center for Science in the Public Interest says canned soups, ice cream, coffee creamers, and nonstick cooking spray are some of the worst offenders. Though most of us have drowned our troubles in an entire pint of ice cream at some point, the serving size is actually half a cup. A full pint contains an entire day's allowance of saturated fat. While people think Fat Free Original Coffee-mate is healthier than straight half and half, when the portions are equalized they have about the same amount of calories and saturated fat. PAM is able to advertise that it contains zero calories and zero fat because the serving is a fraction of a second spray. A full six second spray provides 50 calories and 6 grams of fat.

The group's analysis of Americans' soup consumption is particularly thorough:

Canned soup presents a dramatic example of how unrealistic the stated serving sizes are, according to CSPI. Labels for Campbell's Chunky Classic Chicken Noodle soup indicate a serving is 1 cup (a little less than half a can) and has 790 milligrams of sodium-a hefty amount by any standard and about half the sodium most adults should consume in a whole day. But according to a national telephone survey commissioned by CSPI, 64 percent of consumers would eat the whole can at one time and would consume 1,840 mg of sodium-more than a day's worth for most adults. Only 10 percent of consumers said they eat 1 cup portions.

Similarly, CSPI's survey found that 62 percent of consumers eat the contents of the entire can of a (reconstituted) condensed soup like Campbell's Chicken Noodle Soup. An entire can holds 2,390 mg of sodium-far more than the 890 mg listed for one serving. That amount of sodium only applies if one can is divided into 2½ portions. Another 27 percent eat half a can at a sitting, so they get 1,195 mg.

I actually was aware that you're not supposed to eat the whole can of soup in one sitting. I was saved from the perils of excess sodium consumption by reading the damn label. Though even if you do take a look at the packaging, it's clear Campbell's doesn't care about making its nutritional information clear. The portion size may be 2.5 servings, but no one in their right mind is saving a half cup of chicken noodle soup for a rainy day.

However, the problem isn't entirely the food manufacturers. A large part of it is that portion sizes are out of control in the U.S.. Michael Jacobson, CSPI's executive director, says,

"Over the years we've looked and laughed at many serving sizes, and these are some of the foods where the label serving is just so different from what people actually consume."

Nutrition labels definitely need to be modified, but making them reflect what most Americans actually eat isn't the answer either. The key is to post reasonable serving sizes, not realistic portions. People may eat 18 Oreos at a time, not 3 as the box suggests, but Nabisco doesn't need to give that serving its seal of approval.